“All of the concerned cases involved people who were already seriously ill,” Susanne Stöcker, spokeswoman from the Paul Ehrlich Institute (PEI) in Berlin, told RBB info radio.
Responsible for approving the vaccines used in Germany, the PEI is hoping to counter public fears immunisation could pose more risks than the actual swine flu virus.
Citing a PEI report, daily paper Bild said on Thursday there had been 11 cases of serious allergic reactions to the immunisation. In most cases, the symptoms appeared 40 minutes after receiving the shot.
Another six people, one of whom was epileptic, suffered from a neurological reaction. The others experienced a variety of symptoms, including a tingling in the right arm, headache, disorientation and double vision.
Bild also reported there have been three cases leading to cardiovascular symptoms and three instances of autoimmune reactions such as fainting and serious infections.
In recent days, there have been two deaths occurring after immunisation for swine flu: a 83-year-old man in Saxony and a small child in Berlin.
Since the vaccine became available, more than 1.5 million people in Germany have been immunised, according to the PEI. Of those, doctors have recorded 652 adverse reactions in 197 patients, aged 10 months to 92 years.
As of Thursday morning, there have been 22 confirmed deaths in Germany caused by swine flu out of more than 60,000 cases. Health authorities confirmed on Monday that two men from Bavaria died from swine flu complications.
German officials believe the rate of new infections has accelerated to 15,000 a week, making it increasingly urgent that people in the high-risk category such as small children and pregnant women become vaccinated.